Process for the manufacture of formaldehyde from methane



- May 16, 1933. NASHAN 1,909,215

PROCESS FOR THE MANUFACTURE OEgFQRMALDEHYDE FROM METHANE Filed Jan. 6. 1930 in but an incomplete measure,

that it was impossible to obtain Patented May 16, 1933 I UNITED {STATES PATENT OFFICE PAUL NASHAIN, OF OBERHAUSEN, GERMANY, ASSIGNOR '10 THEFIRM: GUTE HOFF- NUNGSHUTTE .AKTIENGESELLSCHAIFT, OF OBEBHAUSEN, GERMANY PROCESS non THE mforAc'rmm or roamLmmYnE mom mama:

Application filed January 6, 1930, Serial 1%.

The synthesis of formaldehyde from methane and oxygen represents a problem the technical solution of which has frequently been attempted. The processes hitherto propounded have in most cases proved a failure. dueto the fact that conversion was effected with the result --yields. with any degree of economy.

It has been proposed by way of example to conduct metha ne mixed with air over contacts consisting of copper and pumice-- stone, or, a mixture of air and methane through a so;called ozonizator. Similarly 1t is known that methane may be oxidized by using bark as a contact at tem eratures between 30 and 50 deg. Cent. ccording to another suggestion, it is proposed to bring the mixture of methane and oxygen, the lat-. ter predominating in the mixture, to reaction over a, metal catalyst at 150 and 200 deg. Cent. It has also been proposed to use carbonic acid instead of oxygen, the carbonic acid being mixed with m thane and conducted over a metal contact t a temperature of 500 to700 deg. Cent.

The processes refer ed to did not 'find their way into practical use, due to the low yield not permitting them to be carried out with any degree of j'onomy. The new process ifynoteworthy on account of its being simple f'nd economical in opera-- tion. According to the invention, a m xture of methane and oxygen is brought into the field of a high-trequency current of vary high voltage'injwhich a vacuum is malntained and visiljle discharges are caused to take place, forprnaldehyde and water being immediately ned between the two poles. Reaction apparently takes place according to the formula But even in the absence of catalyst, the yield is substantially increased by using a vacuum.- The two gases, methane and oxygen,

418,978, and in Germany November 15, 1928.

gases. Thus, coke gas, which containsabout 25 per cent. of methane, may be used when mixed with air.

The drawing shows a device for carrying out the process. I

1 is a. high-frequency generator, 2 the transformer and 3 the produced high-frequency field in which a vacuum is maintained and to which the mixture of air and methane is conducted by the circuit 4. Air and methane flow through the pipes 5 and 6 into the pipe 4. After passing through the highfrequency field, the mixture enters the washer 7 into which washing liquor is admitted by the sprayer 8. The solution of formaldehyde is drawn 01f at the bottom of the washer in the container 9. The residual gas escapes at 10.

v1. A mixture of lpart of air and 1 part of n"' thane is conducted through an electric field which is defined by high frequ'ency currents at a voltage of 80,000 and 400,000 cycles-at a speed of 1 centimetre per second. 350 grammes of formaldehyde per -cubic metre of methane may be washed out of the liberated gas.

2. An electric high-frequency field of 90,- 000 volts and 300,000 cycles is charged with copper oxide. A mixture of 1% parts of air and 1 part of methane is conducted over the oxide of copper at a pressure of 200 millimetres of mercury and a speed of 2 centimetres per second. The liberated gas contains 480 grammes of formaldehyde per cubic metre of methane.

What I claim is:

1. Process for the manufacture of formaldehyde from methane and oxygen, consisting in conducting the two gases through an\ electric'field in which visible discharges of a high frequency current of very high voltage are caused to take place, and maintaining 'a vacuum in the reaction room.

2. Process for the manufacture of formaldehyde from methaneand oxygen, conso I PAUL NASHAN. 

